Scale chart



APY 6 1943- I B; w. KING 2,315,710

SCALE CHART Filed July 17, 1939 ATTORNEY` Patented Apr. 6, 1943 UNITED STATES PATENT QFFICE SCALE CHART Application July 17, 1939, Serial No. 284,962

6 Claims.

This invention relates to a chart for scales. The invention is concerned particularly with a chart of the drum type wherein the cylindrical surface of the drum upon which the indicia is provided is constituted by a metallic sheet.

Among the objects of the invention is the provision of an arrangement in the seam structure of the metallic sheet, which forms a nice clean line at the joint which does not project beyond the periphery of the drum so that the sight wire can be placed in close proximity to the surface. The seam structure is such that the metallic sheet is strongly held in cylindrical form, and may be made and completed before the cylindrical metal form is mounted upon wheels or spiders. A further object is an improved arrangement in the securing of the drum to the supporting wheels or spiders. The material of the metallic sheet is preferably light metal such as aluminum or aluminum alloy. Other objects will become apparent as the detailed description progresses.

Fig. 1 is a perspective view of a chart constructed in accordance with the invention, showing some of the parts in dotted lines.

Fig. 2 is an enlarged cross sectional view taken substantially on line 2-2 of Fig. 1.

Fig. 3 is a perspective view showing a portion of the seam structure.

Fig. 4 is a cross sectional View taken substantially online 4-4 of Fig. 3.

Fig. 5 is an enlarged cross sectional view showing the connection between the edges of the drum and a spider frame.

Fig. 6 is a view showing the manner of forming the joints shown in Fig. 5.

Fig. '7 is a view showing a modified manner of securing the flanges.

The chart structure may take the form of the usual general structure heretofore employed, and may include a central axis shaft l upon which are mounted wheels or spiders 2, each having a peripheral flange 3. The spokes of the wheels may be slotted as at 4 and each spoke may be equipped with an adjustable weight such as a screw and nut, as shown at 5, for balancing the structure.

The surface-forming member comprises a sheet of light metal such as aluminum or aluminum alloy, as indicated at I0, and this is fashioned into cylindrical form. Suitable indicia are used on the surface, and to this end the exterior surface of the sheet may be given a lithographic white coat which is a sort of flexible enamel. The indicia are printed upon this enameled surface. As shown in Fig. 1, the indicia includes numbers in- Cil dicating the weight and numbers used for the computing purposes.

lThe edges of the cylinder are turned inwardly as at ll into abutting relationship, thus leaving an exterior surface without any projections thereon with only a line lla visible from the outside. The flanges l l are secured together after the manner illustrated in Figs. 4 and 7. This arrangement embodies punching out portions of the flanges and folding the punched out portions over each other as shown at l2. The punched out metal forms apertures I3, but the metal is left intact on one side of the apertures so that the ears or projections l2 may be turned back upon themselves and upon the flange. The flanges may be secured together eyelet fashion, as shown in Fig. 7, where the metal is punched out and fashioned back as at IZa around a central aperture 13a.

At the ends of the drum the flange is cut away, as illustrated, leaving a narrow slot It, the flanges being cut away preferably to an extent to nicely accommodate the flange 3 of the spider.

In fashioning the chart, the surface is preferably lithographed while the metal is in flat form, and then the cylinder of sheet metal is fashioned after the manner above described. The length of the sheet is preferably accurately predetermined so that when the sheet is fashioned with flanges Il of determined extent, a cylinder of predetermined diameter is formed. The flanges may be cut away before or after the fashioning of the cylinder. The cylinder, while being held in a suitable jig or holder, is completed by the punching out of the tabs l2 and the turning over of the tabs upon themselves. The next step is to take a spider which has been accurately formed, and it is pushed into the end of the cylinder preferably until the edge of the flange is flush with the edge of the cylinder. Then the spider for the other end is pushed into said other end in the same manner. The axis rod I may be assembled to the spiders in any suitable manner.

Since the drum is self-sustaining and has a definite diameter it need only be attached t0 the wheels in such a manner as to prevent relative rotary or axial movements. A preferred manner of connecting means is illustrated in Figs. 5 and 6. The edge portions of the cylinder and the flanges 3 are provided with aligned openings It, and a body of soft metal is placed in these openings. This soft metal may be lead or an alloy of lead or other soft metal or alloy, and may be of a spherical shape as indicated at ll. This body of soft metal is now crushed with suitable tools or one tool having two jaws, one being illustrated at i3 which is flat for engaging the outer surface, and the other being illustrated at l 9 which has a recess 26. The flat surface of the part I8, and indeed the uppermost surface of the lower part I9 may have a curvature corresponding to the curvature of the drum. When these tools are brought together the soft metal is crushed or fashioned into a shape substantially as illustrated in Fig. 5, thus forming a rivet-like device Ila. The flat tool I8 causes the upper surface of the securing device to lie substantially flush with the exterior surface of the drum, While the recess 20 accommodates the excess metal and forms a head-like device l'ib on the underside. The pressure causes the soft metal piece to be deformed and spread laterally to tightly engage in the aligned apertures.

With this arrangement the securing device Ila is only required to hold the wheel and drum together with a shear action. rEhe securing devices eifectively prevent relative rotary movements between the drum and the wheels and prevent the wheels and drum from shifting relatively axially. There is no need of holding the drum radially inward against the periphery of the wheels because the drum is capable of maintaining its own shape.

After this assembly has been made the drum may be balanced by shifting the weights 5, but this is an old practice having long since been carried out in connection with the same type of spiders used with paper charts. The paper chart had an overlapped seam which caused an unbalanced condition which was taken care of by the adjusting of the weights 5, and so in this case, the flange l I is balanced. The seam structure of the paper chart and the seam structure of this metallic chart constitute only one factor in any initial unbalanced condition. The seam Il and the securing devices l1 form no projecting structure on the drum, with the result that an indicating wire can be placed very closely to the drum which is a desirable feature. The strength of the drum is such that no center wheel or spider is needed, although in some cases a center spider may be used if the same should be found desirable. Such a center spider would have a rim formed to accommodate the seam iiange il.

I claim:

1. In a scale chart, a sheet of light thin metal fashioned into cylindrical form, the adjacent edges of the sheet being turned straight inwardly in abutting relation and being secured together, leaving a substantially unobstructed outer surface at the seam, the inturned edges terminating short of the edges of the drum, and a wheel with a rim tted within each end of the drum and outwardly of said inturned edges.

2. In a scale chart, a sheet of light thin metal fashioned into cylindrical form, the adjacent edges being turned inwardly toward the center of the drum and disposed in abutting relation, separate portions stricken out of overlying portions oi the edges and fashioned back upon the inturned edges with one portion disposed upon the other, said inturned edges terminating short of the edges of the drum, and a wheel with a rim fitted within each end of the drum and outwardly of said inturned edges.

3. In a scale chart, a sheet of light thin metal fashioned into cylindrical form, the adjacent edges being turned inwardly toward the center of the drum and disposed in abutting relation, separate tabs stricken out of overlying portions of the edges and fashioned back upon the inturned edges with one tab disposed upon the other, said inturned edges terminating short 0f the edges of the drum, and a wheel with a rim tted within each end of the drum and outwardly of said inturned edges.

4. In a scale, a sheet of light thin metal fashioned into cylindrical form, the adjacent edges being turned inwardly toward the center of the drum and disposed in abutting relation, individual eyelet-like parts stricken out of overlying portions of the edges, leaving apertures therein with the stricken out metal turned back upon the inturned edges, said inturned edges terminating short of the edges of the drum, and a wheel tted within each end of the drum outwardly of the inturned edges.

5. In a scale chart, a sheet of light thin metal fashioned into cylindrical form, means adjacent the edges of the sheet turned straight inwardly in abutting relation and being secured together, leaving a substantially unobstructed outer surface at the seam, the inturned means terminating short of the edges of the drum, and a wheel with a rim disposed within each end of the drum in contact with the inner side of the drum and outwardly of said inturned means.

6. In a scale chart, a sheet of light thin metal fastened into cylindrical form, means adjacent the edges of the sheet turned inwardly and disposed in abutting relation and being secured together, leaving substantially an unobstructed outer surface at the seam, said inturned means being positioned inwardly from the edges of the cylinder and a wheel with a rim fitted Within each end of the cylinder and outwardly of said inturned means.

BERT W. KING. 

